JP2012135847A - Thread fastening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thread fastening device capable of preventing a worker from forgetting setup work.SOLUTION: The thread fastening device 1 includes a driver tool 4 having a driver bit 4c on a fore end, and an arm 3 which supports the driver tool 4 and is movable in the horizontal direction and the vertical direction. A worker holds the driver tool 4, operates it above a workpiece, and lowers it to the target thread fastening point to perform the thread fastening work. The thread fastening device 1 includes rotary encoders 14, 23, 34 for detecting position information of the driver tool 4, and a control unit 50 which presets the thread fastening point, the waiting position point at the position different from that of the thread fastening point, and a passing order of these points, collates these points with the present position of the driver tool 4 for determination, and indicates the fact that the driver tool 4 does not pass the points according to the preset order.

Description

  The present invention relates to a screw tightening device for an operator to hold and operate a driver tool attached to an arm and perform a screw tightening operation.

  Conventionally, as a screw tightening device for performing a screw tightening operation by an operator holding a driver tool attached to an arm movable in the horizontal and vertical directions and operating the driver tool to a desired position, Patent Document 1 (Japanese Patent Laid-Open Publication No. 2002-133). No. 346857) is known. The screw tightening device includes position detecting means for detecting position information of the arm. The control unit is configured to collate and determine the current position information of the arm and a preset screw tightening point, and display the result. Further, a tightening order of a plurality of screw tightening points is also set in the control unit, and when the operator makes a mistake in the tightening order, a message to that effect is displayed. This configuration is intended to reduce operator errors.

JP 2002-346857 A

  However, the above-described screw tightening device does not correspond to mistakes in the setup work such as changing the screw size corresponding to each screw tightening point or replacing the work, and does not completely prevent work mistakes.

  In view of the above problems, the screw tightening device of the present invention comprises a driver tool having a driver bit that rotates by driving of a rotational drive source at the tip, and an arm that supports the driver tool and is movable in the horizontal and vertical directions. In the screw tightening device configured to perform the screw tightening work by the operator holding the driver tool and operating it over the workpiece and lowering it to the target screw tightening point, the position information of the driver tool is detected. The position detection means, the screw tightening point, the standby position point at a position that is not the screw tightening point, and the order of passing these points are set in advance, and these points and the current position of the driver tool are collated and determined in advance. If the driver tool does not go through in the order specified, the control is configured to display that effect. And a stage.

  In addition, when a sensor for detecting the presence or absence of a workpiece is provided and the control means is interlocked with the sensor and the driver tool is waiting at the standby position, the detection signal from the sensor is not switched. It is desirable to be configured to display.

  According to the screw tightening device of the present invention, the standby position point is set, and at the standby position point in addition to the screw tightening point, the collation determination with the current position of the driver tool is performed. Thus, by the cycle management incorporating the screw tightening point and the standby position point, at the standby position point, it is practically recommended to perform the setup work to the worker, and work errors can be reduced.

It is a whole block diagram in the screw fastening apparatus of this invention. It is a planar view enlarged sectional view which shows the raising / lowering movable mechanism in the screw fastening apparatus of this invention. It is a front view expanded sectional view which shows the raising / lowering movable mechanism in the screw fastening apparatus of this invention. It is a partially cutaway expanded sectional view which shows the turning movable mechanism in the screw fastening apparatus of this invention. It is a partially cutaway expanded sectional view which shows the horizontal movable mechanism in the screw fastening apparatus of this invention. It is explanatory drawing which shows the image of the collation determination by the control unit in the screw fastening apparatus of this invention. The struts and arms are shown schematically. It is an external view of the control unit in the screw fastening apparatus of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a screw tightening device, which moves up and down along a support column 2 erected in the vertical direction, and an arm 3 that moves on a horizontal plane, and a driver tool that is attached to the arm 3 and moves integrally therewith. 4 is provided. The driver tool 4 is attached to the tip of the arm 3, and the bracket 5 is attached to the rear end of the arm 3 so that it can be moved up and down along the support column 2 and can pivot together with the support column 2.

  In addition, a sensor 6 as an example of a workpiece detection means is disposed on a loading table (not shown) on which a workpiece is loaded. The sensor 6 detects the presence / absence of a workpiece, and the detection signal is configured to be transmitted to a control unit 50 described later in detail.

  The arm 3 is configured to be movable up and down along the support column 2 by an elevating movable mechanism 10 shown in FIGS. 2 and 3. The elevating movable mechanism 10 includes a pulley 11 that is pivotally supported above the column 2, a belt 12 that is wound around the pulley 11 so as to cover the column 2, and a weight 13 that is attached to one end of the belt 12. It is composed of The bracket 5 is attached to the other end of the belt 12, and when an operator grips the start grip 4 a of the driver tool 4 and operates the arm 3 in the vertical direction, gravity acts on the weight 13. The arm 3 is configured to move up and down along the support column. And the rotary encoder 14 which is an example of a position detection means detects the rotation amount of the pulley 11. FIG. Thereby, it is comprised so that the raising / lowering position information of the arm 3 may be detected. That is, as shown in FIG. 6, the rotary encoder 14 detects the Z-axis coordinate of the driver tool 4 in the spatial coordinates where the vertical direction is the Z-axis, the horizontal turning direction is the X-axis, and the horizontal direction is the Y-axis. It is configured.

  Further, the arm 3 is configured to freely swivel and move along a horizontal plane integrally with the support column 2 by a swivel movable mechanism 20 shown in FIG. The swivel movable mechanism 20 meshes with the first spur gear 21 that is rotatably attached to the lower end of the support 2 and the first spur gear 21, and is used to rotate the first spur gear 21. The second spur gear 22 rotates with the rotation. Thereby, the support | pillar 2 turns with the turning of the arm 3, the 1st spur gear 21 also rotates, and the 2nd spur gear 22 also rotates with this. The rotary encoder 23 detects the amount of rotation of the second spur gear 22 and detects the turning position information of the arm 3 in the horizontal plane. That is, in the spatial coordinates shown in FIG. 6, the rotary encoder 23 is configured to detect the X-axis coordinates of the driver tool 4.

  Further, the arm 3 is configured to be freely movable in a direction (horizontal direction) orthogonal to the X axis and the support column 2 by a horizontal movable mechanism 30 shown in FIG. The horizontal movable mechanism 30 includes a rail 31 and a guide block 32 that guides the movement of the rail 31, and the arm 3 is attached to the tip of the rail 31. A gear 33 is pivotally supported in the vicinity of the rear of the rail 31, and an outer tooth 31 a that can mesh with the gear 33 is formed at the rear end of the rail 31. As a result, when the operator operates the arm 2 to move it horizontally, the gear 33 rotates. Then, the rotary encoder 34 detects the amount of rotation of the gear 33 and detects horizontal movable position information of the arm 3 that moves horizontally. That is, the rotary encoder 34 is configured to detect the Y-axis coordinates of the driver tool 4 in the spatial coordinates shown in FIG.

  The driver tool 4 includes a motor 4b as a drive source at an upper portion thereof, and the rotational drive of the motor 4b is configured to be transmitted to a driver bit 4c at the tip via a driver shaft (not shown). Further, as a means for starting the driving of the motor 4b of the driver tool 4, the mechanism disclosed in FIG. 2 of Japanese Patent Application Laid-Open No. 07-1347 is provided. Although details are omitted, when the operator depresses the start grip 4a of the driver tool 4 downward, a built-in start switch (not shown) is operated to rotate the driver bit 4c. The driver tool 4 is connected to the control unit 50 via the driver controller 40, and the driver controller 40 is configured to control the driving of the motor 4b in response to a command from the control unit 50.

  Further, the driver bit 4c is configured such that its tip can be engaged with a drive hole in the screw head, and a ring-shaped magnet 4d is attached to the driver bit 4c. As a result, the driver bit 4c is magnetized, and the screw can be electromagnetically attracted.

  Information detected by the rotary encoders 14, 23, 34 is transmitted to the control unit 50 via the encoder cables 14a, 23a, 34a. Thereby, the position information of the driver tool 4 in the space coordinates is detected.

  The control unit 50 is configured to store one or a plurality of screw tightening points and a standby position point on the workpiece as a teaching program in a built-in storage unit (not shown). The position information (X, Y coordinates) of the screw tightening point or the position information (X, Y coordinates) of the standby position point and the position information (X, Y coordinates) of the driver tool 4 are collated and determined. Has been.

  Then, as shown in FIG. 7, the collation result (match / mismatch) is displayed on the collation lamp 55 arranged near the monitor 51 of the control unit 50. In the case of coincidence, the collation lamp 55 is turned on, and in the case of inconsistency, the collation lamp 55 is turned off to visually notify the collation result to the operator. Moreover, different sounds flow from the speaker 54 according to the collation result, and the collation result is also audibly notified to the operator. Further, when they do not coincide with each other, a drive stop signal is issued to the driver controller 40 so that the motor 4b is not driven even if the operator depresses the start grip 4a.

  The control unit 50 is configured to detect torque from the load current value of the motor 4b of the driver tool 4. The torque management is set to be performed in addition to the collation determination. In view of this, the control unit 50 is set with an optimum torque range at the time of screw tightening. When the screw tightening is normally performed, the OK lamp 52 is lit, and the screw tightening is out of the torque range. When it is performed, that is, when tightening is abnormal, the NG lamp 53 is turned on.

  The control unit 50 is preset with a passing order including both the screw tightening point and the standby position point, and manages this as one cycle. Then, the control unit 50 collates and determines these points and the current position of the driver tool 4, and when the driver tool 4 does not pass through the preset order, the control unit 50 displays that fact and the driver controller 40. The driver tool 4 is configured not to be driven even if the operator issues a drive stop command to the operator and depresses the start grip 4a.

  Here, the standby position point is set to a position that is not a screw tightening point. In other words, this standby position point is used to perform setup work such as exchanging the screws corresponding to each screw tightening point on the work, or replacing the work. The tool 4 is made to wait. Thus, the cycle management incorporating the standby position point can prevent the operator from skipping the setup work.

  For example, when the workpiece is replaced at the standby position point, the control unit 50 interlocks with the sensor 6 and the detection signal from the sensor 6 does not switch while the driver tool 4 is waiting at the standby position point. In this case, that is, when the replacement of the work cannot be confirmed, the fact is displayed on the monitor 51 and the driving of the driver tool 4 is stopped.

  On the other hand, when replacing the screw corresponding to the next screw tightening point at the standby position point, only the coordinate collation determination is performed without interlocking with the sensor 6. In this case, it is desirable that the standby position point is set outside the work. As a result, if a box containing various screws is arranged at the standby position point and is replaced with a screw corresponding to the next screw tightening point at the standby position point, the operator will not forget to replace the screw.

  With the above-described configuration, the screw tightening device 1 of the present invention prompts the operator to perform setup work, and can further prevent work errors by making a determination according to the content of the setup work.

  Here, the standby position point can be used for cycle management in which a series of operations are counted in addition to the above-described setup operation. For example, in a cycle in which screws are tightened to a plurality of screw tightening points, a standby position point is set at the beginning or end of the cycle. If the matching between the driver tool 4 and the standby position point coincides after the screws are tightened in a predetermined order, this is counted and stored. In this way, by grasping the number of workpieces that have been completed, process management at the manufacturing site is enhanced.

  By the way, in the collation judgment by the control unit 50, as shown in FIG. Due to these collation determination areas A and B, the control unit 50 allows the position information (X, Y coordinates) of the screw tightening point and the position information (X, Y coordinates) of the driver tool 4 to coincide with each other without any error. Even if not, if the driver tool 4 is located in the area, it is determined as a match. Specifically, a rectangular horizontal plane area centered on an arbitrary point on the Z-axis line (vertical line) passing through the screw tightening point is stored as the collation determination areas A and B. In addition, the collation determination area has a different width depending on the lift position (Z-axis coordinate) of the driver tool 4 and is set narrower in the downward direction. That is, in the spatial coordinates, the collation determination area has an inverted cone and is set to be gradually narrowed.

  In the screw tightening operation using the screw tightening device 1, the operator roughly moves the driver tool 4 horizontally above the target screw tightening point before the collating operation. Then, the collation work is performed while referring to the collation result by the collation lamp 55 or the speaker 54. Here, in the position where the dry tool 4 is positioned upward and the distance between the driver tool 4 and the screw tightening point is long and the matching of visual matching is relatively difficult, the matching determination area is set wide. On the other hand, in the position where the driver tool 4 is located near the screw tightening point and the matching of the matching by visual observation is relatively easy, the matching confirmation area is set narrow. With this setting, the operator lowers the driver tool 4 while finely adjusting the horizontal position of the driver tool 4 according to the collation result by the collation lamp 55 or the speaker 54 to match the collation. Then, it becomes possible to easily guide the driver tool 4 to the target screw tightening point and tighten the screw.

  On the other hand, a collation determination area C having a predetermined area is also set at the standby position point. However, since the screw tightening operation is not performed here, it is not necessary to form an inverted cone as in the collation determination areas A and B at the screw tightening point, and for example, a cylinder may be formed.

DESCRIPTION OF SYMBOLS 1 Screw fastening apparatus 2 Support | pillar 3 Arm 4 Driver tool 4a Start grip 4b Motor 4c Driver bit 4d Magnet 5 Bracket 6 Sensor 10 Lifting movable mechanism 11 Pulley 12 Belt 13 Weight 14 Rotary encoder 14a Encoder cable 20 Turning movable mechanism 21 First flat Gear 22 Second spur gear 23 Rotary encoder 23a Encoder cable 30 Horizontal movable mechanism 31 Rail 31a External teeth 32 Guide block 33 Gear 34 Rotary encoder 34a Encoder cable 40 Driver controller 50 Control unit 51 Monitor 52 OK lamp 53 NG lamp 54 Speaker 55 Reference lamp

Claims (2)

A driver tool having a driver bit that rotates by driving of a rotational drive source and an arm that supports the driver tool and is movable in the horizontal and vertical directions. In the screw tightening device configured to operate with and lower the target screw tightening point to perform the screw tightening work,
Position detecting means for detecting position information of the driver tool;
Preset the stand-by point and the passing order of these points in advance to the screw tightening point and the position that is not the screw tightening point, collate and judge these points and the current position of the driver tool, and follow the preset order A screw tightening device comprising: a control unit configured to display a message when the tool does not pass through.   A sensor for detecting the presence / absence of a workpiece is provided, and if the detection signal from the sensor is not switched while the driver is waiting at the standby position in conjunction with the sensor, the fact is displayed. The screw tightening device according to claim 1, which is configured as described above.

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